A new switch -a was added to print both reachable and unreachable
hosts. To diffentiate, hosts are now colored based on their status.
The -a switch overrides -r and -d.
By default, pinger will not lookup hostnames for IPs that are
unreachable. This prevents extended times if dead IPs do not have host
entries. However, there are also cases where DNS resolution is
important even when the IP is unreachable. pinger now supports this
using the -f flag.
